Posts Tagged ‘Green Articles’

A team of Indian engineers has designed a prototype low-cost solar-heated water desalination unit that can produce about five litres of drinking water each day and is intended for use by rural households.

The desalination unit may be used to turn brackish groundwater fit for drinking at any place with abundant solar energy, the team of engineers, who are from the National Institute of Technology in Kurukshetra and an engineering college in Bangalore, have said.

The laboratory-scale desalination unit they have built and tested in Bangalore produces five litres of drinking water on a sunny day and costs less than Rs 7,000, the engineers said.

More drinking water may be extracted in regions with greater sunshine and if the glass surface collecting solar energy is increased. The engineers described their design in the journal Current Science, published by the Indian Academy of Sciences, last week.

“This is a start — we wanted to see whether this idea works,” said Praveen Hunashikatti, a Bangalore-based team member who had worked on the project while doing his MTech at NIT Kurukshetra. “It looks promising but needs to be improved.”

Over 70 per cent of India’s estimated 600,000 villages use groundwater as their main source of drinking water, drawing it through pumps or wells. But much of this groundwater is brackish and contaminated with metallic ion impurities, from fluorides and nitrates to arsenic.

A report from the Central Ground Water Board, released in 2010, had documented that salt levels in groundwater from over 60 per cent of India’s landmass were beyond human taste limits.

Desalination units based on the reverse osmosis technology have already been installed in some rural areas, but reverse osmosis requires a steady supply of electricity and also generates waste water.

There are also solar-heated desalination units that use parabolic dishes that automatically change their orientation as the sun’s position changes through the day.

“Parabolic dishes that track the sun and change their orientation are expensive and unlikely to be affordable by average rural households,” said Kambalipura R. Suresh, professor of civil engineering at the BMS College of Engineering, Bangalore, and another team member.

The prototype from the Kurukshetra-Bangalore team will need to be scaled up to match the efficacy of the solar-heated desalination units that use parabolic dishes.

Hunashikatti calls the prototype a “coupled system” — a glass collector and a set of long tubes with air evacuated from them to avoid loss of heat. The slope of the glass collector and the orientation of the evacuated tubes are tailored to the latitude of the location.

The desalination is based on conventional distillation —evaporation and condensation. The solar energy, Hunashikatti explained, heats the water, which causes layers of hot water to move upward, evaporate and condense on the glass from where it can be extracted.

“This coupled system is our alternative to automatic tracking — instead of chasing the sun, we orient the slope and the tubes to retain maximum heat,” Suresh told The Telegraph.

A larger glass slope will mean more solar radiation and increase the amount of water generated.

In laboratory tests, the prototype was able to reduce the levels of fluorides, chlorides, nitrates, calcium carbonate, magnesium carbonate, and calcium in samples of water to levels below the acceptable limits for drinking water.

“A scaled-up version will need to be tested at multiple locations for different groundwater and sunshine conditions,” said Basavaraju Prathima, an environmental engineer at the BMS College and a team member.

Step 1: Windows Energy Saving Features

Windows has built in features to save energy

Go to the control panel, and click “Power Options.” Select a power saving power plan. Then go to “Choose When to turn off the display.” My personal preference is to turn off the display after five minutes idle, and sleep after ten minutes.

Step 2: Physically Reducing Power Consumption

Downlclocking your components reduces the speed at which they operate, but will also reduce power consumption and head production. You can downclock your video card with software like ATItool and EVGA precision tool. Contrary to it’s name, ATItool also works on nVidia cards.

Step 3: CPU Power Features

Both Intel and AMD CPU’s have power saving features that downclock your CPU when it is not under load. AMD had Cool n Quiet, and Intel has Enhanced Speedstep. These features will need to be enabled in your bios, and with windows xp, the latest AMD drivers have to be installed for Cool n Quiet to work

You can check if these features are working with a free program called cpu-z

Step 4: Other

Lower the brightness on your monitor when it is dark out.

Buy an 80+ certified power supply. These guarantee 80 percent efficiency at many load levels.

Here’s a simple one: Don’t leave your computer on when you’re not using it!

There are other green components you can buy such as hard drives.

The new HD 4890 video cards automatically downclock themselves when they idle, and use significantly less power than the 4870 and 4850 do on idle.

You can permanently downlclock your cpu, but i don’t know how to do that. You can also lower the core voltage of your cpu, but if you do not lower the multiplier/fsb along with it, it will probably not be very stable.

The biggest power plant turning refuse into electricity has officially been taken into use on Wednesday in Vantaa. The new plant will produce 920 gigawatt-hours of heat and 600 GWh of electricity each year by burning rubbish collected across Uusimaa.

Vantaan Energia officially opened its new waste-to-energy incinerator on Wednesday. The new plant is Finland’s biggest of its kind, and will produce half of the district heating demand and 30 percent of the electricity needed in the municipality of Vantaa.

The facility has been thoroughly tested, with the first waste entering the system this spring. It’s the biggest investment the local electricity company has ever made, replacing one unit at the company’s existing incinerator in Malminlaakso.

30% cut in CO2 footprint

Around 320,000 tonnes of rubbish will arrive at the plant every year, before it is sorted and incinerated to produce some 920 gigawatt-hours of heat and 600 GWh of electricity. That will reduce Vantaan Energia’s carbon output by 30 percent.

The plant’s emissions will be monitored continually, and the unit will be shut down if it exceeds a certain limit. Handling waste in this way is becoming more common in Finland, but the country still lags behind neighbouring Sweden. Some 90 percent of Swedish waste is recycled or used to produce energy, while in Finland the corresponding figure is just 40 percent.